UTRAN (Universal Terrestrial Radio Access Network) is a term that identifies the radio access network of a UMTS (Universal Mobile Telecommunications System), wherein the UTRAN consists of Radio Network Controllers (RNCs) and NodeBs i.e. radio base stations. The NodeBs communicate wirelessly with mobile user equipments and the RNCs control the NodeBs. The RNCs are further connected to the Core Network (CN). Evolved UTRAN (E-UTRAN) is an evolution of the UTRAN towards a high-data rate, low-latency and packet-optimised radio access network. Further the E-UTRAN consists of NodeBs, and the NodeBs are interconnected and further connected to the Evolved Packet Core network (EPC). E-UTRAN is also being referred to as Long Term Evolution (LTE) and is standardized within the 3rd Generation Partnership Project (3GPP).
A user equipment (UE) in the E-UTRAN may be in either an idle mode or a connected mode. Based on UE mobility and activity while in the connected mode the E-UTRAN may direct the UE to transit between a number of radio resource control (RRC) sub-states: Cell_PCH, URA_PCH, Cell_FACH and Cell_DCH state. UEs with high transmission activity should be in Cell_DCH state, where power-controlled dedicated channels are established to and from the UE. In Cell_DCH state, the UE is assigned dedicated radio and hardware resources, which minimizes processing delay and allows for high capacity. UEs with low transmission activity should be in Cell_FACH state, where only common channels are used. In Cell_FACH state, no dedicated hardware resources in the NodeB are needed. UEs with no transmission activity are idle, i.e. in Cell_PCH or URA_PCH states, which enables very low UE power consumption but does not allow any data transmission.
In the context of 3GPP release 8, the application of Enhanced Uplink in the Cell_FACH state is discussed to improve the uplink transmission. Thus, the UE should be able to send uplink data in Cell_FACH state with higher throughput than what is possible today. For this purpose, the UE will need to use an enhanced dedicated channel (E-DCH) as soon as possible and without transiting to Cell_DCH state, as the transition to Cell_DCH state would imply communication with the RNC. Briefly, the discussed fast E-DCH access procedure, as illustrated in FIG. 1, would be:    1. The NodeB broadcasts the configuration of the common E-DCH, which can be used for uplink traffic in CELL_FACH state.    2. The UE starts the Random Access Channel (RACH) procedure.    3. The NodeB sends a response to the UE and additionally it sends codes, timing offsets and any other additional information to the UE enabling the UE to transmit data on allocated resources of the common E-DCH. No interaction with the RNC is required.    4. The UE starts transmitting data using the resources allocated by the NodeB. Whether NodeB was able to allocate resources to the UE on the common E-DCH the UE will omit the data part of the RACH procedure and continue to transmit data on the E-DCH. However, the UE will use the data part of the RACH procedure whether no resources could be allocated on the common DCH.    5. When the UE has no more data to send, the NodeB releases the common E-DCH resources.